Sleep isn’t just essential to recharge our bodies. It plays an important role in all aspects of our health, from maintaining a healthy weight to improving physical fitness. Except many of us walk around daydreaming about those elusive 7 to 8 hours of solid sleep we’re supposed to get each night. We bemoan our inability to log the right quantity and quality of sleep, but we rarely talk about another aspect of sleep that experts say matters just as much, if not more: keeping a schedule.

“People focus on getting enough sleep and that’s important, but a lot of people don’t emphasize the importance of a consistent sleep/wake schedule,” Rachel Salas, M.D., an associate professor of neurology at Johns Hopkins Medicine specializing in sleep medicine, tells SELF. Even if you’re clocking plenty of hours of sleep, if your bedtime and wake time changes every day, “studies show you’re going to function like a sleep-deprived person,” says Salas. Ignoring consistency makes getting enough quality sleep even more difficult.

When your schedule is all over the place, your circadian rhythm, or body clock, doesn’t have a chance to normalize. Your internal body clock is one of the most important factors driving sleepiness and wakefulness, Joseph Ojile, M.D., medical director of the Clayton Sleep Institute, tells SELF. “When [your life and circadian rhythm] line up correctly, you have a much better chance of getting to sleep and getting up when you want,” Ojile says. If you don’t have a consistent schedule, your body struggles to give you the right cues when you need them.

It’s more important to have a strict wake time versus bedtime, Ojile adds. Or, more specifically, to be exposed to your first ray of light at the same time every day—that’s the crucial piece of the puzzle. Light travels through the optic nerve in your eye to a part of the brain called the suprachiasmatic nucleus. “That thing controls circadian rhythm, or body’s drive to have wake and sleep,” Ojile says. “Morning light also signals to the SCN what time you should actually go to bed. It tells your body, ‘Oh, you got up at 6, so you probably should try to go to bed at 10,’” he explains. “It all works together.” Once you set your wake time, you can find the bedtime that lets you clock enough zzz’s.

No surprise, experts say “catching up” on lost sleep generally isn’t effective. But if you have to do it, Ojile says it’s better to go to bed earlier rather than sleep in. Short naps also help.

What about sleeping in just an extra half hour or so? Salas says she has patients with very sensitive body clocks, so even a half hour difference can throw them off. But for the most part, 30 minutes of wiggle room should be OK. “What we don’t want is for people to become so strict that they get stressed out over it,” says Ojile.

The important thing is getting back on schedule as promptly as possible. “If you’re a healthy sleeper, you’ll catch up during the week by just doing the right thing,” he says. You’ll mess up your cycle even more if you sleep in later to try and log more shut-eye, so you’re better off returning to a regular routine and pushing through the first day or two of tiredness until your body gets back on track.

Consistency ultimately begets quality and quality. When your circadian rhythm is in sync with your schedule and environment, you can fall asleep faster instead of tossing and turning when you should be off in dreamland. Salas suggests nailing down a routine first and foremost, even if you’re not getting as much sleep as you should be. “If you know why you’re sleep-deprived and know you can only get six hours, put more of an emphasis on trying to be consistent as best as you can so you don’t have two things going against you,” she says. Eventually, you may find you’ll start getting the sleep your body’s been telling you it needs.

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